Theres a standard color code for the boating industry that I wanted to use but some of the colors needed were only sold in 500' spools so I just went with the colors available in shorter lengths. All wiring and connectors were anchor brand. Heatshrink
everything... . If your batteries are in the stern its best to keep the switch back there if not you'll need a lot of 4/0 cable @ $4/ ft
A fool proof electrical system is a lot of money but seeing that every time I was ever stranded it was because of electrical problems.